First Proof That Ghrelin Increases Appetite and Food Intake in Humans

Intravenous ghrelin infusion potently increased appetite, food intake, and GH secretion in healthy humans — the first demonstration that ghrelin drives human hunger, not just rodent appetite.

Wren, A M et al.·The Journal of clinical endocrinology and metabolism·2001·Strong EvidenceRCT
RPEP-00705RCTStrong Evidence2001RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
RCT
Evidence
Strong Evidence
Sample
Not reported

What This Study Found

IV ghrelin infusion in healthy humans increased subjective appetite ratings and food intake significantly, alongside GH stimulation, providing the first proof that ghrelin is a human hunger hormone.

Key Numbers

How They Did This

Randomized, placebo-controlled study in healthy volunteers. IV ghrelin infusion with subjective appetite visual analog scale ratings and ad libitum buffet food intake measurement. GH measured.

Why This Research Matters

Confirming ghrelin drives human appetite transformed it from an interesting lab finding to a validated drug target. It justified developing ghrelin-based drugs for cachexia, anorexia, and potentially obesity (via antagonists).

The Bigger Picture

This landmark study confirmed the animal findings in humans, validating ghrelin as the hunger hormone and launching a new era of appetite biology and drug development.

What This Study Doesn't Tell Us

Healthy volunteers; responses in patients with appetite disorders may differ. IV administration may not predict responses to long-acting formulations. Acute study doesn't predict chronic appetite effects.

Questions This Raises

  • ?Can ghrelin treatment help cancer cachexia or anorexia nervosa?
  • ?Does chronic ghrelin elevation lead to sustained appetite increase?
  • ?Can ghrelin antagonists suppress human appetite for obesity treatment?

Trust & Context

Key Stat:
First human proof IV ghrelin increased both hunger ratings and actual food intake in healthy humans — confirming the hunger hormone works in people, not just rats
Evidence Grade:
Strong evidence from a placebo-controlled study with both subjective (appetite ratings) and objective (food intake) endpoints in humans.
Study Age:
Published in 2001. This landmark study has been cited extensively and confirmed by numerous subsequent human ghrelin studies.
Original Title:
Ghrelin enhances appetite and increases food intake in humans.
Published In:
The Journal of clinical endocrinology and metabolism, 86(12), 5992 (2001)
Database ID:
RPEP-00705

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Does ghrelin really make you hungry?

Yes — this study proved it in humans for the first time. When healthy people received ghrelin, they felt hungrier and ate significantly more food. It's truly the body's hunger hormone.

Could this help people who can't eat?

Potentially. People with cancer, HIV, or eating disorders who can't eat enough might benefit from ghrelin to stimulate their appetite. Ghrelin-based drugs for cachexia and appetite disorders are being developed.

Read More on RethinkPeptides

Cite This Study

RPEP-00705·https://rethinkpeptides.com/research/RPEP-00705

APA

Wren, A M; Seal, L J; Cohen, M A; Brynes, A E; Frost, G S; Murphy, K G; Dhillo, W S; Ghatei, M A; Bloom, S R. (2001). Ghrelin enhances appetite and increases food intake in humans.. The Journal of clinical endocrinology and metabolism, 86(12), 5992.

MLA

Wren, A M, et al. "Ghrelin enhances appetite and increases food intake in humans.." The Journal of clinical endocrinology and metabolism, 2001.

RethinkPeptides

RethinkPeptides Research Database. "Ghrelin enhances appetite and increases food intake in human..." RPEP-00705. Retrieved from https://rethinkpeptides.com/research/wren-2001-ghrelin-enhances-appetite-and

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.